High resolution observations of chromospheric lines in late-type dwarfs.
Abstract
High resolution H-alpha absorption- and emission-line profiles are reported for 11 stars of spectral types ranging from K5V to M3V, and the profiles of NaI(D), HeI(5876A), and CaII(IR) are given for portions of the sample. The observations were taken with the Qubes spectrograph, and the data are reduced by comparing the spectral data with observations of bright K giants of known radial velocity. Emission characterized by a strong blue H-alpha wing is reported for the active dMe stars, and the dMe G1616.2 demonstrates evidence of binarity in three separate lines. Chromospheric lines in absorption are identified in the remaining sources, and differences between the present and previously observed values are elaborated. The differences, particularly in H-alpha, are concluded to indicate intrinsic variability in the stars by either filling-in of absorption lines or by significant changes in the photosphere and chromosphere.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- November 1991
- Bibcode:
- 1991A&AS...90..437P
- Keywords:
-
- Chromosphere;
- Dwarf Stars;
- Late Stars;
- Stellar Spectra;
- Ultraviolet Spectra;
- Absorption Spectra;
- H Alpha Line;
- High Resolution;
- Visible Spectrum;
- Astrophysics